The present invention is directed to a flexible partition or curtain with an integrated roller wind-up apparatus. In particular, the present invention relates to a torque-balanced motorized roller system for controlling the vertical position of a flexible partition or curtain.
It is known to utilize flexible sheet type curtains, which are adapted to be rolled up and down, to divide or partition a large room such as a gymnasium. In most cases, an electric motor drives a shaft on which the curtain is hung. U.S. Pat. No. 3,900,063 discloses a motor and primary roller device mounted adjacent to the trusses or rafters supporting a ceiling. An upper end of the curtain is attached to the primary roller and the lower end can be varied in vertical position by rolling and un-rolling the primary roller. The weight of the curtain is supported in part on secondary rollers that are positioned below the primary roller, which is vertically movable based on the amount of curtain material wound on to the primary roller.
U.S. Pat. No. 5,524,693 discloses a flexible partition or curtain for dividing a room that has a top edge suspended from a ceiling, and a bottom edge touching the floor when the curtain is fully deployed. An elongated cylinder is connected to the curtain to extend from one side edge to the other to divide the curtain into upper and lower portions. A motor is located at one end of the cylinder and connected to rotate the cylinder so that the upper and lower portions of the curtain will be wound up on the cylinder when it is required to roll up the curtain. A torque reacting mechanism, in the form of an arm fixed to the motor exterior of the cylinder and at a right angle to the axis of the cylinder, includes a second winding element mounted on the arm with a flexible sheet suspended from the ceiling parallel to the upper portion of the curtain. The flexible sheet is winds onto the second winding element in a counter-rotational direction so as to counteract the torque of the motor.
Assuming the same rotational speed for the cylinders in both these prior patents, the roller of U.S. Pat. No. 5,524,693 should lift the lower edge of the curtain faster than the roller disclosed in U.S. Pat. No. 3,900,063. However, the load placed on the flexible sheet on the second winding element requires that the flexible sheet itself be subject to minimum or negligible stretching characteristics. Additionally, while the curtain of U.S. Pat. No. 5,524,693 should lift faster, during descent the flexible sheet on the second winding element may not provide the correct rotational reaction to the curtain unwinding if the descent is too fast. Consequently, the lowering speed may be required to be less than the raising speed. Additionally, if the lowering speed is too great, the arm holding the second winding element could rise and even flip over rendering the torque balance effect useless.
There remains a need for even better systems for raising and lowering a flexible partition or curtain using an integrated roller wind-up apparatus.